Conductive polymers having highly enhanced solubility in organic solvent and electrical conductivity and synthesizing process thereof

ABSTRACT

The present invention relates to a new process of synthesizing conductive polymers from monomers substituted with amine group. The process provides simple synthesizing steps for the conductive polymers without using other additives such as stabilizers or emulsifiers. The conductive polymers synthesized according to the present invention have highly enhanced solubility in common organic solvents and electrical conductivity compared to conventional conductive polymers. Therefore, the conductive polymers synthesized according to the present process can be utilized in applications that require high electrical conductivity, for example an electromagnetic interference shield or a transparent electrode of thin film, as well as in specific applications such as various conductive films, fibers, polymer blends, battery electrodes or conductive etch mask layers.

This application claims the benefits of Korean Patent Application No.2004-33168, filed on May 11, 2004 in Korea and Korean Patent ApplicationNo. 2005-0032461, filed on Apr. 19, 2005, which are herein incorporatedby reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to conductive polymers, and moreparticularly to conductive polymers which have highly enhancedsolubility in organic solvents and electrical conductivity, andsynthesizing process thereof.

2. Discussion of the Related Art

Conductive polymers have conjugated structures along double bondspresent in the backbone thereof and has much enhanced electricalconductive properties compared to other organic materials because theconductive polymers form partial electrical charges along the conjugatestructures and thereby having unlocalized electrons when the polymersare doped with dopants such as a protonic acid. Because the conductivepolymers have both enhanced electrical, magnetic or optical propertiescomparable with conventional metals and satisfactory mechanicalproperties and processability as conventional polymers, they have beenremarkably attracted in the filed of chemistry, physics, materialengineering and industries.

The first developed conductive polymer is polyacetylene, which wasdeveloped by Shirakawa et al., however, polyacetylene is oxidized easilyin the air. After polyacetylene was developed, Conductive polymers suchas polyaniline, polypyrrole, and polythiophene have been developed.

The conductive polymers can be used in various applications according totheir electrical conductivity. For example, the conductive polymers withelectrical conductivity of 10⁻¹³˜10⁻⁷ (S/cm), 10⁻⁶˜10⁻² (S/cm), andequal to and more than 10⁰ (S/cm), respectively have been used asantistatic materials, static discharge materials, and electro-magneticinterference(EMI) shielding materials, battery electrodes, semiconductorand solar cells. Accordingly, the conductive polymers may be utilized inmore various applications by improving their electrical conductivities.

Among intrinsically conducing polymers, polyaniline has been noticed inthe relevant field since it is not only cheap and very stable comparedto polypyrrole and polythiophene also doped easily by protonic acids.

The polyaniline (PANI) can be classified into the completely reducedfrom, leucoemeraldine, the intermediated oxidized form, emeraldine, andthe fully oxidized form, pernigraniline, according to its oxidationstate.

However, the conductive polymers synthesized through the conventionalprocesses, especially the polyaniline as the completely reduced from,leucoemeraldine, the intermediated oxidized from, emeraldine salt, andthe fully oxidized form, pernigraniline, have disadvantages that theycannot be made from melting process owing to their high boiling pointand that they must experience complex processing steps since they havelow solubility in solvents with high-boiling point or universal orcompatible solvents such as meta-cresol.

In order to improve the problems of the conductive polymers as indicatedabove, copolymers such as aniline derivatives or graft copolymers havebeen synthesized by inducing various side chains into the benzene ringor amine group of the conductive polymers for improving solubility ofthe backbone of the conductive polymers. Alternatively, various dopants,or other organic materials, polymers or plasticizers are added into theconductive polymer for improving the processability and the electricalconductivity of the conductive polymers. However, those composites havelower electrical conductivity compared to the conductive polymers beforereforming.

Polyaniline (PANI) can be synthesized either by electro-chemical chargetransfer reaction which uses electro-chemical reaction or by chemicaloxidation process that uses protonation through acid-base or redoxreaction. However, it has been known that the chemical oxidation processis suitable for producing polyaniline in industrial scales.

Representative chemical oxidation process for synthesizing polyanilinehas been reported to MacDiarmid et al., who synthesized polyaniline bypolymerizing aniline monomers dissolved in hydrochloric acid withoxidizing agents such as ammonium persulfate in aqueous solution in thetemperature of 1˜5° C., separating and washing the precipitates and thenobtaining polyaniline (See A. G. MacDiarmid, J. C. Chiang, A. F.Richter, N. L. D. Somarisi, in L. Alcacer (ed.), Conducting Polymers,Special Applications, Reidel, Dordercht, 1987, p. 105). The MadDiarmidprocess have been utilized widely and regarded as a standard method forproducing polyaniline.

The polyaniline of emeraldine base (EB) synthesized according to theMacDiarmid process has low molecular weight (intrinsic viscosity 0.8˜1.2dl/g), but it is dissolved in 1-methyl-2-pyrrolidon (NMP). Also it hasreported that emeraldine salt produced by doping the EB with10-camphorsulfonic acid (ES-CSA) is dissolved a little in meta-cresol.The film made from that solution containing ES-CSA has at mostelectrical conductivity of about 100 S/cm, on the other hand, the filmmade from emeraldine salt doped with hydrochloric acid (ES-HCl) showshighly lower electrical conductivity of about 5 S/cm. However, it needsto be separating not dissolving portion from the dissolved portion inthe MacDiarmid process. Especially, the polyaniline synthesizedaccording to the MacDiarmid process has low molecular weight, broadmolecular weight distribution, and inferior solubility to solvents orelectrical conductivity resulted from side chain reactions to thebackbone. Therefore, there remains a need of improving themicro-chemical structure or electrical conductivity of polyanilinesynthesized according to the MacDiarmid process.

In order to improve the disadvantages and inferior processability of thepolyaniline synthesized by MacDiarmid process, a lot of researches whichuse emulsion polymerization have been suggested. For example, U.S. Pat.No. 5,232,631 and U.S. Pat. No. 5,324,453 to Cao et al., which areincorporated herein by reference, disclose process for synthesizingpolyaniline by dissolving aniline monomers and functionalized protonicacid in polar solvents such as water, mixing the solution with anorganic solvent to prepare an emulsion, and then adding an oxidizingagent into the emulsion. Cao et al. reported that the emeraldine salt(ES) can be dissolved in nonpolar solvent such as xylene becauseemulsifier acts as a dopant, and therefore, it is reacted with thepolyaniline to form composite. However, since Cao et al. usesfunctionalized protonic acids as emulsifier, it is difficult to controldoping the emulsifier and the process requires commonly expensivematerial. Further, since the functionalized organic acid is hardlyseparated from polyaniline after polymerizing reaction, the conductivepolymers may have only very limited uses and highly inferior electricalproperties. For instance, the emeraldine salt, which synthesizedaccording to Cao et al, doped with dodecyl benzene sulfonic acid (DBS)has a solubility of less than 0.5% and an electrical conductivity ofonly about 0.1 S/cm.

Kinlen of Monsanto produced polyaniline salt by preparing reverseemulsion system comprising an organic solvent such as 2-butoxyethanolsoluble in water and an organic acid, which is not soluble in water butsoluble in the organic solvent, as a hydrophobic emulsifier, mixing ananiline monomer and a radical initiator with the emulsion system andpolymerizing the mixture to form polymer solution that has an organiclayer, which contains polyaniline salt, separated from an aqueous layercontaining the radical initiator and non-reacting compounds. (See U.S.Pat. No. 5,567,356; Kinlen, Macromolecules, 31,1745 (1998), which areincorporated herein by reference). Kinlen reported that the polyanilinesalt was soluble in nonpolar solvents of no less than 1% (w/w). However,it is difficult to synthesize polyaniline because the radical initiatorin the aqueous layer is separated from the monomer in the organic layerand polyaniline synthesized according to Kinlen process has lowelectrical conductivity owing to difficulty of control doping process.For example, it was reported that polyaniline salt synthesized withdinonyl naphthalene sulfonic acid as a hydrophilic organic acid had anelectrical conductivity of about 10⁻⁵ S/cm in case the salt ismanufactured as pellets.

Harlev et al. synthesized polyaniline salt with the MacDiarmid processexcept using pyruvic acid instead of hydrochloric acid (See U.S. Pat.No. 5,618,469, which is incorporated herein by reference). It ispossible to improve processability of polyaniline by using pyruvic acidbecause pyruvic acid functions as organic solvent as well as dopant.However, since pyruvic acid has lower acidity it is difficult to dopepolyaniline by pyruvic acid. Accordingly, polyaniline doped with pyruvicacid has low electrical conductivity, and especially in case thepolyaniline doped with pyruvic acid is used as a transparent electrode,it has very high apparent surface resistance as much as 20,000 Ω/square,which is very high electrical resistance for the transparent electrode.

Ho et al., produced polyaniline through emulsion system prepared byadding specific emulsifier into an organic mixture solvent comprising ananiline monomer and a protonic acid with stirring (See U.S. Pat. No.6,030,551, which is incorporated herein by reference). According to Hoet al., both a radical initiator such as benzoyl peroxide and thepolyaniline is dissolved in the same non-aqueous layer, and therefore,it is possible to synthesize polyaniline solution in situ withoutresidual solids. However, since it is not easy to separate thenon-aqueous layer from an aqueous layer, it is expected that polyanilinesynthesized according to Ho process may not have high electricalconductivity.

U.S. Pat. No. 6,072,027 to Carey et al., which is incorporated herein byreference, discloses a producing method of polyaniline with highlyenhanced polymerization yield, by using chlorate salt or hydrochloricacid combined with bi- or trivalent iron salt as a new oxidizationinitiator.

Palaniappan et al. disclose a process for the preparation of polyanilinesalt by forming inverted emulsion system that comprises an aqueous layerand an organic layer using a surfactant and then polymerizing theinverted emulsion system at room temperature using a radical initiatorsuch as benzoyl peroxide dissolved in the organic layer (See U.S. Patentpublication No. 2002-00062005, U.S. Pat. Nos. 6,586,565 and 6,630,567,which are incorporated herein by reference). However, polyaniline filmprepared from Palaniappan process has very low electrical conductivity,for example about 0.1 S/cm, and may be only used in much limitedapplications since it is impossible to raise molecular weight ofpolyaniline.

In addition to emulsion polymerization as above, polyaniline synthesisprocesses through a dispersion polymerization, in which monomers such asaniline is fully dissolved in reacting solvent while synthesizedpolymers are not dissolved in the solvent, have been reported. Forexample, Armes et al. reported the polymerization process whichcomprises stabilizing sterically the conductive polymer by designingparticular stabilizer and then particularizing the conductive polymer(See Armes et al., handbook of Conducting Polymers, Elsenbaumer ed. M.Dekker, New York, 1996, Vol. 1, p. 423). In this dispersionpolymerization, since most of the stabilizer covers with thepolyaniline, the polyaniline in aqueous solution can be prepared.However, the synthesized polyaniline has a particle size of about 60˜300nm, which is affected by the stabilizer, and has low electricalconductivity, which defines its application.

Further, there have been reported that polyaniline is synthesized inaqueous solution containing organic solvents. Geng et al. preparedpolyaniline film, which has electrical conductivity of about 10 S/cm,through synthesizing polyaniline with organic solvents such as ethanol,THF, and acetone (See Geng et al., Synth. Metals. 96, 1 (1998)).However, since it needs very long polymerization reaction time in Gengprocess, a probability of side reaction is raised.

According to Beadel et al., the polyaniline produced by the standardsynthesizing method disclosed in MacDiarmid as described above hashigher electrical conductivity as it has higher molecular weight.Accordingly, the monomer needs to be reacted or polymerized at lowertemperature in order to enhance molecular weight of the polymer (SeeBeadel et al., Synth. Met. 95, 29˜45, 1998). For lowering reactingtemperature, when aniline monomer is polymerized in homogeneous aqueoussolution system, metallic salts such as LiCl, CaF₂ and the likes areusually added to the system in order to prevent the system fromfreezing. However, mixing those metallic salts with the solution systemcauses the reaction to being slow, that is to say, at least 48 hours tocomplete the polymerizing reaction, and therefore, it is difficult tocontrol the polymerization reaction. Also, as lowering the reactiontemperature, the synthesized polyaniline has an increased molecularweight as well as molecular weight distribution (polydispersity of equalto or more than 2.5).

Also, there form side chains as the aniline monomer is added into aquinonediimine group in intermediate chains. Accordingly, FeCl₂ as anoxidizing agent is added during polymerization reaction in order toinhibit formations of the side chains in polyaniline, or the polyanilineis eluted with organic solvents for removing side products such asoligomers which quit synthesis during the polymerization reaction.Besides, since the monomers are added into the polyaniline on theortho-positions as much as the para-positions of the benzene ring in thepolyaniline backbone in case of emulsion polymerization or interfacialpolymerization, such synthesized polyaniline has much side chains, whichcause the polyaniline to have lower electrical conductivity andsolubility.

According to Thyssen et al., there is a probability of about 10% of theortho coupling, which induces side chains in the backbone of thepolymers, when the aniline monomers are polymerized by usingelectro-chemical process (See Thyssen et al., Synth. Met. 29, E357˜E362,1989). Such polymers synthesized by ortho-coupling has lower hydraulicdimensions, which results in decreased intrinsic viscosity, compared topolymers synthesized by para-coupling, i.e. polymers without sidechains. In other words, the polymers synthesized by ortho-coupling hasmuch side chains and has more molecular weights even though they havelow intrinsic viscosity of equal to or less than 1.2 dl/g. Accordingly,the polymers synthesized by ortho-coupling has inferior processabilitywithout improving the electrical conductivity.

Moreover, Huang et al. produced polyaniline of nano-fiber form bypreparing a system which comprises an organic layer and an aqueous layerimmiscible with the organic layer, dissolving an aniline monomer in theorganic layer, and an initiator and an organic acid in the aqueouslayer, and polymerizing the monomer in the interface (See Huang et al.,J. Am. Soc. 125, 314 (2003)).

Min of Dupont Technology reported that conductive polymer with highyield could be obtained by increasing level of LiCl or NaCl as additivein the MadDiarmid process, as described above, up to 5-10 M at 0° C. for3 hours (See G. Min, Synth. Met., 119, 273, (2001)).

In addition to the patents and references described above, manyresearches were reported for improving physical or chemical properties,for example electrical conductivity of the conductive polymers (OrganicConductive molecules and Polymers, Vol. I-IV, Ed. By H. S. Nalwa, JohnWiley & Sons, New York, 1997; Handbook of Conducting Polymers Vol. I,II, Ed. By Skotheim et al., Marcel Dekker, New York, 1998; ConductivePolymers, P. Chandrssekhar, Kluwer Acade. Pub. Boston, 1999; ConductiveElectroactive Polymers by G. G. Wallace, G. M. Spinks, L. A. P.Kane-Maquire, P. T. Teasdale, 2^(nd) ed. CRC Press, New York, 2003).

However, the polyaniline producing processes disclosed to date make useof introducing substituents into monomers or mixing the monomers withimmense amount of additives such as stabilizer or emulsifier, andtherefore, it is difficult to obtain pure polyaniline. Also, becausepolyaniline according to conventional processes has synthesized byortho-coupling as much as para-coupling and frequently forms side chainsby side reactions, such polyaniline does not have high electricalconductivity, which limits its applications.

Also, polypyrrole has been synthesized mainly by electrochemicalsynthetic process. In case of synthesizing polypyrrole by theelectrochemical process, unlike synthesizing polyaniline, acids are notadded during polymerization, which makes the reaction simplify. However,when polypyrrole is synthesized according to the chemical process, sidereactions such as inter-chain crosslink or side chain addition to thebackbone of polypyrrole frequently happened, which causes synthesizedpolypyrrole to not dissolving in common solvents and thereforedeteriorates processability. In case of synthesizing polypyrrole byelectrical process, solvents or counter ions of conductive plate havehighly affects on physical properties of polypyrrole.

Lee et al. prepared of conductive polypyrrole powder by reacting pyrrolemonomers at 0° C. for 40 hours using chloroform and dodecyl benzenesulfonic acid (DBSA) of the same molar equivalents of chloroform (See J.Y. Lee, D. Y. Kim, C. Y. Kim, Synth. Met. 74, 103 (1995)). DBSA adoptedby Lee et al. acts as both dopant and surfactant. However, polypyrrolefilm sample synthesized by Lee et al. has very low electricalconductivity of about 5 S/cm.

Besides, chemical process for synthesizing polypyrrole in organicsolvents such as CHCl₃, THF, or CH₃N₂O has been tried in order toproduce polypyrrole being able to dissolve in the organic solvents.However, such synthesized polypyrrole did not have electricalconductivity at all.

Ames et al. reported a process for preparing stable colloidalpolypyrrole by using poly-vinylalcohol, poly-ethyleneoxide, orpoly-vinylpyridine as a steric stabilizer dissolved in water (See Armeset al., Handbook of Conducting Polymers Elsenbaumer ed. M. Dekker, NewYork, 1996, Vol. 1, p. 423). However, since polypyrrole powders aresurrounded by a lot of stabilizers, like polyaniline, and thereforepolypyrrole has a very low electrical conductivity.

Accordingly, it may enhance electrical conductivity of polypyrrole bylinking pyrrole monomers on 2, 5 positions between pyrrole ring andsustaining linearity thereof. As mentioned above, pyrrole may be solublein much solvents compared to aniline, however, it is very difficult todissolve oxidizing agent and pyrrole monomer in the same solvent.

The synthetic conductive polymers, especially polyaniline has much lowerreal electrical conductivity than theoretically calculated electricalconductivity, about 10⁵˜10⁶ S/cm (Kohlamn et al., Phys. Rev. Lett.78(20), 3915, 1997), because they does not have fully linear form andform completely orders such as crystalline structure per se. Since suchpolymers with lower electrical conductivity cannot be utilized astransparent plastic electrode or EMI shielding materials, there stillremain needs of development of polyaniline having much improvedelectrical conductivity in the related field.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to conductive polymerswith much enhanced electrical conductivity and solubility to commonsolvents and process for producing the polymers that substantiallyobviates one or more of problems due to limitations and disadvantages ofthe related art.

The present invention is based on a new concept of self-stabilizeddispersion polymerization (referred to as “SSDP”). The use of the term“self-stabilized” herein includes, but is not limited to, the dispersionin the absence of any stabilizers. For example, in contrast withconventional homogeneous or dispersion polymerization using an aqueousmedium containing aniline, pyrrole, acid, and oxidant, this newpolymerization process is performed in a heterogeneous biphasic systemof organic and aqueous medium without any stabilizing additives. Here,the monomers and growing polymer chains act as a stabilizer, resultingin excellent dispersion of the organic phase inside of the aqueousreaction medium.

It is an objective of the present invention is to provide a synthesizingprocess of conductive polymers without using other additives such asemulsifier and antifreeze thereby reducing polymerization reaction time.Accordingly, the conductive polymers of the present invention have muchhighly improved physical property, for example electrical conductivityand solubility to common solvents.

It is another objective of the present invention is to provide aconductive polymer that has highly improved micro-chemical structurewith little structural defects.

Additional features and advantages of the invention will be set forthherein which follows, and in part will be apparent from the description,or may be learned by practice of the invention. These and otheradvantages of the invention will be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, in oneaspect, the present invention provide a process of synthesizing aconductive polymer, the process comprising: (a) mixing a monomercontaining an amine group and an organic solvent with an acid solution;and (b) adding a radical initiator dissolved in a protonic acid into theacid solution to synthesize the conductive polymer.

Preferably, the monomer is mixed with the acid solution prior to theorganic solvent.

Especially, the monomer with or without substituents has a structurerepresented by formula I below.

wherein R₁ is hydrogen, alkyl, or alkoxy group; and each R₂ to R₅ isrespectively hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl,alkyl-thioalkyl, alkanoyl, thioalkyl, aryl-alkyl, alkyl-amino, amino,alkoxy carbonyl, alkyl sulfonyl, alkyl sulfinyl, thioaryl, sulfonyl,carboxyl, hydroxyl, halogen, nitro, or alkyl-aryl.

Also, the monomer with or without substituents has a structurerepresented by formula II below.

wherein R₁ is hydrogen, alkyl, or alkoxy group; and each R₂ and R₃ isrespectively hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl,alkyl-thioalkyl, alkanoyl, thioalkyl, aryl-alkyl, alkyl-amino, amino,alkoxy carbonyl, alkyl sulfonyl, alkyl sulfinyl, thioaryl, sulfonyl,carboxyl, hydroxyl, halogen, nitro, or alkyl-aryl.

It is preferable that the acid used in step (a) of the present inventionmay comprise inorganic acid, and more preferably, the acid is selectedfrom the group consisting of hydrochloric acid, sulfuric acid, nitricacid, or phosphoric acid.

Also, the protonic acid in step (b) of the present invention may be aninorganic acid such as hydrochloric acid, nitric acid, sulfuric acid,phosphoric acid, hydrofluoric acid, or hydroiodic acid. The protonicacid of the present invention comprises an organic acid, and preferably,the organic acid is selected from the group consisting of methylsulfonic acid, dodecyl benzene sulfonic acid, antraquinone-2-sulfonicacid, 4-sulfosalicylic acid, camphor sulfonic acid, chlorinated sulfonicacid, trifluoro-sulfonic acid.

It is characterized that the organic solvent in step (a) has asolubility factor of about 17 to about 29. The organic solvent compriseshydrocarbons unsubstituted or substituted with hydroxyl, halogen,oxygen, ketone, or carboxyl group, such as an alkyl halide.

The hydrocarbons substituted with halogen may comprise dichloromethane,pentachloro ethane, 1,1,2,2-tetrachloro ethane, trichloro ethane,trichloro ethylene, dichloro methane, chloroform, ethyl bromide, ethylchloride, dichloro propane, trichloro ethane, bis(2-chloroethyl)ether,dichloro ethyl ether, 1,2-dichloro benzene, or mixtures thereof.

The organic solvent substituted with hydroxyl group may be selected fromthe group consisting of comprise 1-propanol, 2-methyl-2-propanol,1,2-dipropandiol, 1,3-propandiol, isopropyl alcohol, butanol,neopentanol, 2-methoxy ethanol, 2-butoxy ethanol, 2-ethyl-1-butanol,3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 1-pentanol,2-pentanol, 3-pentanol, 1,2-propanediol, 1,5-pentandiol, amylalcohol,2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-methyl-2-pentanol,3-methyl-2-pentanol, 4-methyl-2-pentanol, 2-methyl-3-pentanol,3-methyl3-pentanol, hexanol, ethyl hexanol, heptanol, 3-heptanol,2-methyl-2,4-pentandiol, 2-ethyl-1,3-hexandiol, octanol, 1-octanol,2-octanol, decanol, dodecanol, cyclohexanol, tri-ethylene glycol,di-ethylene glycol, tetra-ethylene glycol, tetra-hydrofurfuryl alcohol,or mixtures thereof.

The organic solvent substituted with oxygen may comprise ethylene glycolmonoethyl ether, ethylene glycol dimethyl ether, ethylene glycolmonomethyl ether, ethylene glycol monobutyl ether, diethylene glycolmonoethyl ether or diethylene glycol monobutyl ether, diethylene glycoldiethyl ether, diethylene glycol dimethyl ether, diethylene glycolmonomethyl ether, 1,4-dioxane, or mixtures thereof.

The organic solvent substituted with ketone group comprises butyl methylketone, methyl-ethyl ketone, 4-hydroxy-4-methyl-2-pentanone,cyclopentanone, diacetone alcohol, 4-methyhl-pentanone,4-methyl-2-pentanone, or mixtures thereof.

Also the organic solvent may comprises common organic solvents such asdiethyl carbonate, benzyl acetate, dimethyl glutarate,ethylacetoacetate, isobutyl isobutanoate, isobutyl acetate, meta-cresol,toluene, xylene, nitrobenzene, tetrahydrofuran, N-methyl-2-pyrolidone,dimethyl sulfoxide, N,N-dimethylformamide, or mixtures thereof.

Moreover, the radical initiator comprises ammonium persulfate, hydrogenperoxide, manganese dioxide, potassium dichromate, potassium iodate,ferric chloride, potassium permanganate, potassium bromate, potassiumchlorate, or mixtures thereof. The ratio of moles of aniline to moles ofradical initiator is from 0.1 to 5, preferably 0.1 to 0.75 and mostpreferably 0.1-0.5.

It is also preferable that step (b) of the present invention isperformed in the temperature of between about −45° C. to about 40° C.Also, the radical initiator and the organic solvent comprises an organicphase, wherein the organic phase comprises about 5˜95% by weight basedupon total aqueous solution.

It is more preferable that the process of the present invention furthercomprises step (c) dedoping the conductive polymer with a base such ashydroxide compounds.

In another aspect of the present invention provide a conductive polymersynthesized by the present process, wherein the conductive polymer has ahollow quadra-angular rod shape and honeycombed network configuration.The conductive polymer synthesized by the present invention is consistedof nanometer particles, and has an apparent density in the range ofabout 0.03˜0.19 measured in ASTM Standard D1895-6.

In still another aspect, the present invention provides a electricalconductive polymer synthesized according to the process above, whereinthe polymer has an electrical conductivity of at least about 300 S/cm.Preferably, the conductive polymer has an electrical conductivity of atleast about 500 S/cm, for example at least about 700 S/cm or at least900 S/cm, more preferably, at least about 1100 S/cm, and mostpreferably, at least about 1300 S/cm.

In further another aspect, the present invention provides a conductivepolymer synthesized according to the present invention, wherein theconductive polymer has a hollow quadra-angular rod shape and honeycombednetwork configuration, wherein the conductive polymer has a repeat unitrepresented by the formula III below and the conductive polymer has atleast one single peak at about 123 ppm of chemical shift and at about158 ppm of chemical shift in a ¹³C CPMAS NMR spectrum and/or hasidentifiable peaks at around 140 ppm of chemical shift in a ¹³C CPMASNMR spectrum.

-   -   wherein x and y is respectively a molar fraction of        quinonediimine structural unit and phenylenediamine structural        unit in the repeating unit, and 0<x<1, 0<y<1 and x+y=1; and n is        an integer of 2 or more.

The conductive polymer forms peaks at about 138 ppm of chemical shiftand at about 143 ppm of chemical shift in a ¹³C CPMAS NMR spectrum.Particularly, the conductive polymer has I₁₃₈ larger than I₁₄₃, whereinI₁₃₈ represents a peak intensity at about 138 ppm of chemical shift inthe ¹³C CPMAS NMR spectrum and I₁₄₃ represents a peak intensity at about143 ppm of chemical shift in the ¹³C CPMAS NMR spectrum. Preferably, theconductive polymer has a peak intensity ratio, I ₁₃₈/I₁₄₃, of equal toor more than 1.2 in the ¹³C CPMAS NMR spectrum. Besides, the conductivepolymer has two peaks at about 1107 cm⁻¹ of wavelength in PAS spectrum.

In further still another aspect, the present invention provides apolyaniline having a repeat unit represented by the formula below,wherein the polyaniline has three main peaks corresponding to quaternarycarbon in a solution state ¹³C NMR spectrum in case the polyaniline issubstituted with tert-butoxycarbonyl.

-   -   wherein x and y is respectively a molar fraction of a        quinonediimine structural unit and phenylenediamine structural        unit in the repeating unit, and 0<x<1, 0<y<1 and x+y=1; and n is        an integer of 2 or more.

The conductive polymer synthesized according to the present inventionhas highly linear configuration, fewer side chains, and therefore highlyimproved electrical conductivity compared to polyaniline synthesizedaccording to conventional process. Accordingly, polyaniline of thepresent invention may be used as various conductive films, fibers,coatings, blends with other polymers, battery electrodes, or materialfor organic semiconductors or organic device. Especially, polyanilinesynthesized according to the present invention may be utilized astransparent electrodes, solar cells, conductive etch mask layer or foranti-corrosion, absorbency of near infrared light since composites orcomposition comprising polyaniline of the present invention has highlyimproved electrical conductivity even though low contents ofpolyaniline.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a schematic chemical structure showing the repeating unit ofpolyaniline synthesized according to a preferred example of the presentinvention for describing its particular chemical micro-structure;

FIG. 2 shows a spectrum resulted from ¹³C CPMAS NMR analysis for highlyconductive polyaniline (HCPANI) synthesized according to a preferredexample of the present invention;

FIG. 3 shows a spectrum resulted from ¹³C CPMAS NMR analysis forpolyaniline (PANI) synthesized according to a conventional process;

FIG. 4 shows a spectrum resulted from PAS analysis for highly conductivepolyaniline (HCPANI) synthesized according to a preferred example of thepresent invention;

FIG. 5 shows a spectrum resulted from PAS analysis for polyaniline(PANI) synthesized according to a conventional process;

FIGS. 6A to 6E show respectively SEM electron microscopy of highlyconductive polyaniline of emeraldine base form (HCPANI) synthesizedaccording to the preferred examples of the present invention;

FIGS. 7A to 7E show respectively SEM electron microscopy of polyanilineof emeraldine base form(PANI) synthesized according to the conventionalprocess;

FIG. 8 shows a spectrum resulted from UV-VIS-NIR analysis for emeraldinebase doped with camphor sulfonic acid (EB-CSA) synthesized according tothe present invention;

FIG. 9 a spectrum resulted from solution state ¹³C NMR analysis forpolyaniline synthesized according to the preferred example of thepresent invention; and

FIG. 10 is a graph showing the molecular-weight distribution of highlyconductive polyaniline (HCPANI) synthesized according to the presentinvention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Prior to describing the present invention, polyaniline or itsderivatives synthesized according to the present invention will befrequently referred to as “HCPANI”, while the polyaniline synthesizedaccording to the conventional method will be referred to as “PANI”without indicated otherwise herein. Also, polypyrrole or its derivativesof the present invention will be frequently referred to as “PPy” withoutindicated otherwise herein. In other words, ‘HCPANI’ is intended hereinto mean conductive polymer synthesized from anline monomer which isunsubstituted or substituted as mentioned formula I below, and refer toeach or all of leucoemeraldine form, emeraldine base (EB), emeraldinesalt (ES) or pernigraniline form according to the present invention.

-   -   wherein R₁ is hydrogen, alkyl, or alkoxy group; and each R₂ to        R₅ is respectively hydrogen, alkyl, alkenyl, cycloalkyl,        cycloalkenyl, alkyl-thioalkyl, alkanoyl, thioalkyl, aryl-alkyl,        alkyl-amino, amino, alkoxy carbonyl, alkyl sulfonyl, alkyl        sulfinyl, thioaryl, sulfonyl, carboxyl, hydroxyl, halogen,        nitro, or alkyl-aryl.

Also, ‘PPy’ is intended herein to mean conductive polymer synthesizedfrom anline monomer which is unsubstituted or substituted as describedin formula II below according to the present invention.

-   -   wherein each R₁ to R₃ is respectively as defined in formula I        above.

In the process according to the preferred embodiment of the presentinvention, reactants containing monomer are mixed with 2-phase reactionsystem that comprises an aqueous phase and an organic solution phase.Accordingly, the present process differs from the MacDiarmid standardpolymerizing process. Also, other additives, for example emulsifier,polymeric stabilizer, monomeric and/or oligomeric stabilizer, or othertemplates, are not required principally in the synthesizing process ofthe present invention. Therefore, the present process is differentsubstantially from the conventional emulsion polymerization, suspensionpolymerization, or dispersion polymerization as described above. Thisnew polymerization based upon self-stabilized dispersion concept isreferred to as SSDP. The use of the term “self-stabilized” includes, butis not limited to, the stabilization of biphasic reaction systems by thereactants and polymerization products i.e., the absence of anystabilizers or antifreezes or templates. It is possible that both of twophases of the SSDP process consist of non-continuous phase or continuousphase, however, the aqueous phase may be continuous phase and theorganic solution phase may be non-continuous phase, and vice versa.Particularly, the organic solution phase may be added into the reactionsystem of 5˜95% by weight based on a total aqueous phase.

The aqueous phase in the reaction system of the present inventioncomprises a hydrophilic solvent such as water, a monomer, for example amonomer defined in formula I or formula II above, and an acid,preferably protonic acid, in initiating reaction.

The hydrophilic solvent may comprise water, methanol, ethanol,acetonitrile, 2-methoxy ethanol, or mixtures thereof, and preferablywater alone. The acid may be an inorganic acid or an organic acid whichpreferably has pKa of equal to less than 4.0, more preferably equal toor less than 3.5, and most preferably a protonic acid. Particularly, theacid may comprise an inorganic acid selected from the group consistingof hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid, oran organic acid such as an aryl sulfonic acid or an alkyl sulfonic acid,which is unsubstituted or substituted with halogen, or mixtures thereof.More specifically, the organic acid may comprise an alkyl sulfonic acidsuch as methyl sulfonic acid, or ethyl sulfonic acid, halogenated alkylsulfonic acid, for example chloro sulfonic acid or trichloro sulfonicacid, aryl sulfonic acid such as dodecyl benzene sulfonic acid,anthraquinone2-sulfonic acid, 5-sulfosalicylic acid or camphor sulfonicacid, or mixtures thereof. Preferably, the acid may comprise aninorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, orphosphoric acid.

The organic solution phase in the reaction system of the presentinvention comprises an organic solvent, preferably immiscible ormiscible a little with the aqueous phase or an organic solvent that maybe separated and dispersed with the aqueous phase by soluble selforiented material, which is disclosed in international patentpublication No. WO-02/074833 to the present inventors.

In case of choosing an organic solvent that may be used in synthesizingpolymers, a solubility parameter, which is related with the g molecularweight, density of the polymers, should be considered. Reactions usingvarious organic solvents also produce polyanilines of improved chemicalmicro-structure with similar shapes and conductivity. In a preferredembodiment of the present invention, the organic acid constituted withthe organic solution phase may comprise an organic solvent having thesolubility parameter of between about 17 and about 29.

In a preferred embodiment of the present invention, the organic solventmay comprise hydrocarbons, such as aliphatic, alicyclic, or aromatichydrocarbons, unsubstituted or substituted with hydroxyl, halogen,oxygen, ketone, or carboxyl group, or common organic solvents that maybe used in synthesizing conductive polymers. The hydrocarbons may behalogen-substituted hydrocarbons such as alkyl halides, ether, alicyclichydrocarbons or aromatic hydrocarbons. The hydrocarbons substituted withhydroxyl group comprises C₃˜C₁₋₅ alcohols.

Preferably, the halogen-substituted hydrocarbons comprise a) alkylhalides such as dichloromethane, pentachloro ethane, 1,1,2,2-tetrachloroethane, trichloro ethane, trichloro ethylene, dichloro methane,chloroform, ethyl bromide, ethyl chloride, dichloro propane, trichloroethane, or mixtures thereof; b) ether such as bis(2-chloroethyl)ether,dichloro ethyl ether, or mixture thereof; and c) aromatic hydrocarbonssuch as 1,2-dichloro benzene. Besides, the organic solvent substitutedwith hydroxyl group may comprise 1-propanol, 2-methyl-2-propanol,1,2-dipropandiol, 1,3-propandiol, isopropyl alcohol, butanol,neopentanol, 2-methoxy ethanol, 2-butoxy ethanol, 2-ethyl-1-butanol,3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 1-pentanol,2-pentanol, 3-pentanol, 1,2-propanediol, 1,5-pentandiol, amylalcohol,2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-methyl-2-pentanol,3-methyl-2-pentanol, 4-methyl-2-pentanol, 2-methyl-3-pentanol,3-methyl3-pentanol, hexanol, ethyl hexanol, heptanol, 3-heptanol,2-methyl-2,4-pentandiol, 2-ethyl-1,3-hexandiol, octanol, 1-octanol,2-octanol, decanol, dodecanol, cyclohexanol, tri-ethylene glycol,di-ethylene glycol, tetra-ethylene glycol, tetra-hydrofurfuryl alcohol,or mixtures thereof.

Also, the hydrocarbons substituted with oxygen may comprise ethyleneglycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycolmonomethyl ether, ethylene glycol monobutyl ether, diethylene glycolmonoethyl ether or diethylene glycol monobutyl ether, diethylene glycoldiethyl ether, diethylene glycol dimethyl ether, diethylene glycolmonomethyl ether, 1,4-dioxane, or mixtures thereof.

The organic solvent substituted with ketone group comprises butyl methylketone, methyl-ethyl ketone, 4-hydroxy-4-methyl-2-pentanone,cyclopentanone, diacetone alcohol, 4-methyhl-pentanone,4-methyl-2-pentanone, or mixtures thereof.

Besides, the organic solvent can be used in the present inventioncomprises diethyl carbonate, benzyl acetate, dimethyl glutarate,ethylacetoacetate, isobutyl isobutanoate, isobutyl acetate, meta-cresol,toluene, xylene, nitrobenzene, tetrahydrofuran, N-methyl-2-pyrolidone,dimethyl sulfoxide, N,N-dimethylformamide, or mixtures thereof.

Further, the radical initiator, which is added in the aqueous phaseaccording to the present SSDP process, may comprise ammoniumperoxisulfate, hydrogen peroxide, manganese dioxide, potassiumdichromate, potassium permanganate, potassium bromate, potassiumchlorate, or mixture thereof, and preferably ammonium peroxisulfate. Incase of using ammonium peroxisulfate as oxidizing agent or radicalinitiator, two electrons per 1 mole are related, and therefore, radicalinitiator can be used about 0.1˜5 molar equivalent, preferably about0.1˜0.75 molar equivalent, and most preferably about 0.1˜0.5 molarequivalent (per 1 mole of monomer).

Angelopulos et al. reported that the solubility of the synthesizedpolymers and stability of polymer solution is reciprocal to the amountof the radical initiator (See Angelopulos et al., Synth. Met. 84, 35,1997). Accordingly, it is important to control the addition procedure ofthe initiator as well as the amount of the initiator in the presentinvention. The addition procedure of the initiator may have an affect onthe micro-chemical structures of synthesized polymers because theradical initiator has an affect on the hydrolysis of intermediatessynthesized in the polymerization step.

The polymerization reaction of the present invention is exothermalreaction, and therefore, preferably the reactants are stirred during thereaction. The reaction may be performed in the temperature of −45° C. to45° C., such as −45° C. to 40° C. Preferably, the reaction should beperformed at suitable temperature, which can be determined by desiredmolecular weight, molecular weigh distribution, or electricalconductivity of the synthesized polymers, among the above temperatureranges and keep it during the polymerization reaction because thereaction time and the molecular weigh of the polymers depends on thereaction temperature.

The above reactants are introduced into a reaction vessel to initiatepolymerization. After completing the polymerization reaction, thesynthesized polymers may be separated with various methods according todesired formation of final product. For example, highly conductivepolyaniline (HCPANI) synthesized according to the preferred embodimentof the present invention is washed with water or methanol, and recoveredto obtain emeraldine salt (ES) powder. The ES powder is treated with abase to form emeraldine base (EB) which is very soluble in organicsolvents. The EB form may be doped with various dopants to reprocess itor processed to dope it for various applications. Or the obtained EB maybe manufactured easily to leucoemeraldine form or pemigraniline form byredox reaction.

The SSDP process has main advantage of being able to control molecularweight of produced conductive polymers over the conventional methods. Ina preferred embodiment of the present invention, conductive polymerswith a molecular weight of between about 10,000 and about 385,000 can beobtained by only changing the reaction conditions such as reaction time,temperature, and the likes. Especially, electrical conductive polymersof the present invention had an intrinsic viscosity of about 0.1 toabout 2.9 determined at 30° C. after the conductive polymers weredissolved in sulfuric acid with a concentration of 0.1 g/dl. Also, theelectrical conductive polymers, especially EB, synthesized according tothe present invention has remarkably differentiating micro-chemicalstructure and highly enhanced electrical conductivity compared to EBsynthesized according to the conventional method.

It has been only known that the polyaniline of EB form synthesizedaccording to the conventional method has a fraction ratio of x to y informula III above of about 1:1. In other words, the micro-chemicalstructure of the polyaniline has not been discovered. On the otherhands, HCPANI, which has highly enhanced electrical conductivity and issynthesized according to the present SSDP invention, has remarkablydifferentiating chemical microstructure compared to the conventionalPANI. The differences in chemical structure between the HCPANI and PANIwill be more described in more detail referring the appended drawings.

It is only known that the polyaniline of EB form synthesized accordingto the conventional method has a fraction ratio of x to y in formulaabove of about 1:1. In other words, the microstructure of thepolyaniline has not been fully discovered. On the other hands, HCPANI,which has highly enhanced electrical conductivity and is synthesizedaccording to the present invention, has remarkably characteristicchemical microstructure compared to the conventional PANI. Thedifferences in chemical structure between the HCPANI and PANI will bemore described in more detail referring the appended drawings.

FIG. 1 is a schematic formula showing a repeating unit of polyanilinewith carbon numbers for describing its micro-chemical structure. FIG. 2shows a spectrum resulted from ¹³C CPMAS NMR analysis for highlyconductive polyaniline (HCPANI) synthesized according to a preferredexample of the present invention. FIG. 3 shows a spectrum resulted from¹³C CPMAS NMR analysis for polyaniline (PANI) synthesized according to aconventional process.

As shown in FIG. 2 or 3, HCPANI, which synthesized according to thepresent invention, has two apparent separated peaks around 140 ppm ofchemical shift, that is one peak at about 138 ppm (I₁₃₈) and the otherpeak at about 143 ppm (I₁₄₃) in ¹³C CPMAS (Cross-PolarizedMagnetic-Angle-Spinning) NMR spectrum (FIG. 2). On the other hand, PANIhas blurring multiple peaks at around 140 ppm in ¹³C CPMAS NMR spectrum(FIG. 3).

According to Raghunathan et al., the two peaks (I₁₃₈ and I₁₄₃ in FIG. 2)at around 140 ppm of chemical shift in ¹³C CPMAS NMR analysis of thepolyaniline of EB form corresponds to protonated carbons connected tohydrogen of quinoid ring in repeating unit of polyaniline of EB formshown in FIG. 1 (Raghunathan et al., Synth. Met. 81, 39˜47, 1996; Yasudaet al., Synth. Met. 61, 239˜245, 1993).

However, it is difficult to certify specific peaks at around 140 ppm in¹³C CPMAS NMR spectrum of the PANI synthesized according to theconventional method because there are many small peaks at around 140 ppmof chemical shift as shown in FIG. 3. On the other hand, it wasdetermined that the HCPANI synthesized according to the presentinvention has two or more apparently confirmable peaks, I₁₄₃ and I₁₃₈, ashoulder at around 140 ppm of chemical shift in ¹³C CPMAS NMR spectrumas shown in FIG. 2. Besides, it was determined that the HCPANI hadhigher peak intensity at about 138 ppm of chemical shift than peakintensity at about 143 ppm of chemical shift in ¹³C CPMAS NMR spectrum(I₁₃₈>I₁₄₃). That relationship between peak intensities at specificchemical shifts in ¹³C CPMAS NMR analysis is one characteristic ofHCPANI synthesized according to the present invention, which isremarkably different from peak forms in ¹³C CPMAS NMR spectrum for PANIsynthesized according to the conventional method.

HCPANI synthesized according to the present invention has two noticeablyconfirmable peaks at about 140 ppm in ¹³C CPMAS NMR spectrum, becausethe quinoid ring (quinonediimine structural unit) in the repeating unitof HCPANI in FIG. 1 is connected through immine bonds and thereby notbeing able to rotate and having bended form of —N═bonding instead ofmaintaining linear form. Therefore, 4 carbon atoms (C4) on the quinoidring shown in FIG. 1 lose equivalences. Accordingly, we may infer thatHCPANI synthesized according to the present invention has nearlytheoretically ideal structure of polyaniline as shown formula above. Onthe other hand, since PANI synthesized according to conventional methodhas defects in quinoid ring, PANI has different structure from thestructure of formula above. Accordingly, it is difficult to certifyspecific peaks at around 140 ppm of chemical shift in ¹³C CPMAS NMRspectrum of PANI, which has many indistinguishable peaks around 140 ppm.

Wei et al. reported that Michael addition reaction of aniline monomermight be happened on the quinoid ring as shown below. Therefore, wethink that PANI has other micro-chemical structures than HCPANI.

Further, HCPANI synthesized according to the present invention has asingle or unique peak at about 123 ppm of chemical shift or about 158ppm of chemical shift in ¹³C CPMAS NMR spectrum as shown in FIG. 2. Onthe other hand PANI synthesized according to the conventional methodshows 2 or more unidentifiable peaks at about 123 ppm of chemical shiftand at about 158 ppm of chemical shift ¹³C CPMAS NMR spectrum as shownin FIG. 3

In relation to the differences of peak formation between HCPANI and PANIin ¹³C CPMAS NMR spectrum, a single peak at about 123 ppm of chemicalshift in ¹³C CPMAS NMR spectrum corresponds to carbon atoms C1 and C2 ofbenzenoid ring (phenylenediamine structural unit), which may be rotateda bit in molecules, of the repeating unit of polyaniline in FIG. 1.HCPANI had an equivalent unique or single peak at about 123 ppm in ¹³CCPMAS NMR spectrum (FIG. 2), while PANI showed divided peaks, not uniquepeak, at about 123 ppm in ¹³C CPMAS NMR spectrum (FIG. 3). In otherwords, it is certified that HCPANI of the present invention hasequivalent carbon atoms in benzenoid ring, while PANI does not haveequivalent carbon atoms in benzenoid ring.

Yasuda et al., synthesized polyaniline by adopting Cao et al. (Cao etal., Polymer, 30, 2305, 1989) with using FeCl₃ instead of ammoniumpersulfate which is commonly used in conventional chemical oxidationmethod for producing polyaniline (See Yasuda et al., Synth. Met. 61,239˜245, 1993). However, solid state polyaniline synthesized accordingto Yasuda et al. did not have distinguishable peak, but had onlyindistinguishable small peaks, at about 138 ppm of chemical shift in ¹³CCPMAS NMR spectrum, and showed the peak intensity at about 138 ppm ofchemical shift was lower than the peak intensity at about 143 ppm ofchemical shift.

In other words, conventional PANI has many indistinguishable small peaksat about 138 ppm of chemical shift in ¹³C CPMAS NMR analysis, and thepeak intensity at about 138 ppm is weaker than the peak intensity atabout 143 ppm of chemical shift. On the other hand, HCPANI synthesizedaccording to the present invention has two or more noticeablydistinguished peaks at around 140 ppm in ¹³C CMPAS NMR analysis. HCPANIsynthesized according to the present invention has few defects atcarbons on the quinoid rings of repeating units of polyaniline andaniline monomers is bonded through para-coupling in polymerization. Suchdifferences in micro-chemical structures cause HCPANI to having muchhigher electrical conductivity compared to conventional PANI.

Therefore, it is concluded that HCPANI synthesized according to thepreferred embodiment of the present invention has no, or little defectsin carbons formed on the quinoid ring in the repeat unit thereof andthat aniline monomer is synthesized to the para position of anotheraniline monomer or oligomeric anilines in polymerization, and therefore,HCPANI of the present invention has apparent distinguishable peak ateach about 158 ppm, around 140 ppm, or about 123 ppm in ¹³C CPMAS NMRspectrum. Such differences in micro-chemical structure cause HCPANI ofthe present invention to have much enhanced electrical conductivitycompared to conventional polyaniline (PANI).

HCPANI synthesized according to the present SSDP process has noticeablyspectrum in PAS analysis. FIGS. 4 and 5 are respectively a graphobtained from Photo Acoustic Spectroscopy (PAS) results which aresuitable for obtaining infrared spectrum of polymeric powders such aspolyaniline. FIG. 4 shows a spectrum obtained from PAS analysis forHCPANI powder synthesized according to the present invention, while FIG.5 shows a spectrum obtained from PAS analysis for PANI powdersynthesized according to conventional method. It is generally known thatmorphology of samples has a little affect on absorbency of samples anddoes not have to do with photometry of samples in PAS analysis. Theanalytical results shown in FIGS. 4 and 5 were obtained by treating thepowder forms of HCPANI and PANI under the same analytical conditions,and then comparing quantitatively the infrared absorbencies.

Among infrared absorbency peaks of PAS analysis in FIGS. 4 and 5, thepeak at about 1107 cm⁻¹ of wavelength is assigned to the ring stretchingvibration of the amine (C—N) group in the repeating unit of polyaniline.HCPANI powder has other infrared absorbency peaks at about 1107 cm⁻¹ ofwavelength than the PANI powder synthesized according to theconventional method. HCPANI synthesized according to the presentinvention has two separated peaks at about 1107 cm⁻¹ of wavelength andthe peak intensity at about 1107 cm⁻¹ of wavelength (I₁₁₀₇) isrelatively weak in PAS analysis. (FIG. 4). On the other hand, PANIsynthesized according to the conventional method has a unique peak atabout 1107 cm⁻¹ of wavelength and I₁₁₀₇ is relatively strong (FIG. 5).

In accordance with the preferred example, the peak formation at about1107 cm⁻¹ of wavelength in PAS spectrum is closely related to electricalconductivity of polymers and resulted from structural differencesbetween HCPANI and PANI. In other words, HCPANI has two relatively weakpeaks at about 1107 cm⁻¹, while PANI has a relatively strong unique peakat about 1107 cm⁻¹ of wavelength in PAS spectra.

Besides, it was certified that molecular weight of the conductivepolymer synthesized in the preferred example is closely related to theelectrical conductivity. For example, HCPANI synthesized according tothe preferred example of the present invention with number averagemolecular weights of about 10,000˜30,000 has electrical conductivity ofabout 100˜300 S/cm, while HCPANI with number average molecular weightsof about 30,000˜89,000 has electrical conductivity of about 300˜1300S/cm. In other words, electrical conductivity depends on the molecularweight.

Further, the conductive polymers synthesized according to the preferredexamples of the present invention have enhanced solubility compared tothe conventional polymers. In case HCPANI of conductive EB form has anumber average molecular weight of 15,000, it has solubility of about10% (w/w) in NMP at room temperature, which is about twice as solubilityof polyaniline of EB having the same molecular weight, which is about 5%(w/w) in NMP. Especially, HCPANI with a number average molecular weightof 15,000˜18,000 (intrinsic viscosity of 1.7˜2.7 dl/g) has solubility ofequal to or more than 3% (w/w) in NMP, which is much higher thansolubility of conventional polyaniline with the same molecular weight,which is less than 2% (w/w) in MMP.

The solubility differences between HCPANI of the present invention andthe conventional PANI result from the structural differences betweenthem as well as from particle forms or formation in the polymerization.It was certified that the conductive polymers synthesized according tothe preferred examples of the present invention have specific particlestructure or network configuration because they are polymerized in thereaction system which comprises the aqueous phase and the organicsolution phase but can be self-stabilized.

FIGS. 6A to 6F respectively shows SEM electron microscopy of highlyconductive polyaniline of emeraldine base form (HCPANI) synthesizedaccording to the preferred examples of the present invention, and FIGS.7A to 7E respectively shows SEM electron microscopy of polyaniline ofemeraldine base form (PANI) synthesized according to the conventionalprocess. As shown in FIGS. 6A to 6F, HCPANI of EB form synthesizedaccording to the present invention has cross-sections with variouslengths from about 10 nm to about 50 μm, particularly in particles ofbarrel shapes (FIGS. 6A and 6C). More specifically, each of the HCPANIof the present invention has common structure of having internal holeslike foamed-shapes or honey-comb shapes or having a plurality of compacthollow quadra-angular rod or quadra-angular bar.

Specifically, HCPANI has a plurality of globular particles of 20˜80 nm,which is clustered to form specific network configuration like bunchesof grapes as shown in FIG. 6E, which shows 30,000 times enlarged SEMelectron microscopy of HCPANI. Such a structure allows HCPANI of thepresent invention to have much increased surface areas compared toconventional polyaniline. In contrast, it was observed that PANIsynthesized according to the conventional method forms particles ofprecipitates as shown in FIGS. 7A and 7B.

According to Mandal et al., polyaniline synthesized by dispersionpolymerization has common compact structure or configuration even thoughit has various forms such as needle shape, oblong shape, or sphericalshape (See Mandal et al., Langmuir 12, p 1585, 1996). Besides, Huang etal. reported that polyaniline of nano-fiber form can be obtained bydissolving respectively an aniline monomer in an organic solvent and aninitiator in water and then synthesizing the mixture solution in theinterface (See Huang et al., J. Am. Chem. Soc., 126, p 314, 2003, Angew.Chem. Int. Ed., 43, p5817, 2004). However, HCPANI synthesized accordingto the preferred examples of the present invention has a sort of anetwork configuration, which results in increasing surface area ofHCPANI particles and thereby enhancing solubility thereof. In relationwith the network configuration, it was calculated that HCPANI of thepresent invention had apparent density of between 0.03 g/ml and 0.19g/ml measured in ASTM standard D1895-6, which is very low compared toconventional polyaniline.

As mentioned above, the conductive polymers synthesized according to thepreferred examples of the present invention has much enhanced electricalconductivity and solubility compared to conventional conductivepolymers. However, in case of increasing the electrical conductivity andsolubility of conductive polymers, other additives may be added into thereaction system as templates. For example, precursors of soluble selforiented materials such as a precursor represented by the structurebelow, disclosed in Example 3 of international patent publication WO02-074833 to the present inventors may be mixed with the monomers astemplates into the reaction system.

-   -   wherein each R is —(CH₂)_(n)CH₃, —O(CH₂)_(n)CH₃,        —O(CH₂CH₂)_(n)OCH₃, wherein n is integers between 1 and 24.

The soluble self oriented materials represent by the above structure maybe added into the reaction system of about 5˜30% by weight, preferably5˜25% by weight, and more preferably 10˜20% by weight based on themonomers.

Particularly, the soluble self oriented materials can be mixed with themonomers is a material R is —O(CH₂)_(n)CH₃ (n is integers between 1 and24) in the structure above. Preferably, the soluble self orientedmaterials have side chain (R) of which terminal end may have substitutedwith sulfonic acid (SO₃H), carboxylic acid (—COOH), benzene sulfonicacid (—OC6H4SO3H), benzene carboxylic acid (—OC6H₄COOH), azacrownether,carbazole, thiol (—SH) group.

The synthesizing method of the soluble self oriented material which maybe added in the reaction system of the present invention as template isdescribed in detail in international patent publication No. WO02-074833.

Moreover, it was determined that HCPANI synthesized according to thepresent invention has well-defined micro-chemical structures. FIG. 9shows a spectrum resulted from ¹³C NMR analysis for polyanilinesubstituted with tert-butoxycarbonyl (t-BOC) of the present invention.The micro-chemical structure was investigated for polyaniline derivativeprepared by substituting with tert-butoxycarbonyl (t-BOC) to enhancesolubility in common organic NMR solvents such as CDCl₃.

HCPANI-tBOC of the present invention has four main distinguishable peaksbetween at about 139.5 ppm of chemical shift and at about 160 ppm ofchemical shift in solution state ¹³C NMR spectrum. Among four mainpeaks, three peaks formed at about 140 ppm, about 148 ppm, and about 159ppm of chemical shift in solution state ¹³C NMR spectrum corresponds toquaternary carbons of HCPANI-tBOC. Therefore, it was certified thatHCPANI-tBOC of the present invention forms three main peaks relating toquaternary carbons.

The present invention will be explained in more detail through thefollowing non-limiting examples. However, the present invention will notbe limited to the following examples.

EXAMPLES Measurement of Electrical Conductivity

Electrical conductivity of polymers synthesized in the followingexamples are measured with commonly used four line probe method at roomtemperature in the condition of relative humidity of about 50%. Carbonpaste was used for preventing the polymers from corroding in case ofcontacting gold wires. The electrical conductivity of film samples withthickness of about 1˜100 μm (micron) (sample thickness: t, sample width:w) was measured by calculating voltages (V), currents (i), and distances(l) between 2 internal electrodes and 2 external electrodes connected tothe samples with Keithley instruments.Electrical Conductivity=(l·i)/(w·t·v)

Electrical conductivity was calculated by the above equation (S/cm orSimen/cm). Electrical conductivity was also measured with Van der Pauwmethod, which uses standard four point probe, in order to certify thehomogeneity in electrical conductivity of the samples. The 4 pointmeasurement results were in the range within 5%.

SEM Particle Shape Measurement

Particle formation, structure of configuration of conductive polymerssynthesized in the following examples were analyzed with scanningelectron microscope (SEM, model no. XL-30, Philips Co.). SEM photographsparticles within very restricted region, and therefore, we observed alot of microscopy for obtaining representative images.

Measurement of Molecular Weight with GPC

Synthesized conductive polymers were analyzed with GPC (gel permeablechromatography) for measuring molecular weights thereof. The analysiswas performed with GPC (Water 150 CV, column Shodex, AT-806MS (mixedcolumn)) with NMP as solvent, 1 ml/min at 70° C., which is recommendedin NMP solvent by the manufacturer. Standard sample was polystyrene withmolecular weight of 1300, 3790, 9860, 30300, 65931, 172101, 629440, and995598.

Example 1 Preparation of Highly Conductive Polyaniline (HCPANI)

In this example, highly conductive polyaniline (HCPANI) as emeraldinebase (EB) form was prepared. 100 mL of distilled and purified anilinewas added slowly dropwise into 6 L of 1M HCl and then 4 L of isopropylalcohol was mixed with the solution. The mixed solution was maintainedin the temperature of −15° C. Solution of 56 g of ammonium persulfate((NH₄)₂S₂O₈), as an radical initiator, dissolved in 2 L of 1M HCl wasadded slowly dropwise into the above mixed solution for 40 minutes withstirring to initiate polymerization reaction. After 3 hours, thepolymerization reaction was completed to form precipitate. The obtainedprecipitate was filtered with filter paper and washed with 1 L of 1Mammonium hydroxide (NH₄OH) solution. The precipitate was transferredinto 5 L aqueous solution of 0.1M ammonium hydroxide, stirred for 20hours, washed with water, and then dried with vacuum pump for 48 hoursto yield 1.5 g of polyaniline of emeraldine base (EB).

The synthesized polymer was analyzed with infrared spectroscopy and¹³C-NMR technology. It was determined that the polyaniline synthesizedin this example had a peak at about 1590 cm⁻¹ of wavelength, which isassigned to the ring stretching vibration of typical quinoid ring ofpolyaniline, a peak at about 1495 cm⁻¹ of wavelength, which is assignedto the ring stretching vibration of typical benzenoid ring ofpolyaniline, and a peak at about 3010 cm⁻¹ of wavelength, which isassigned to the ring stretching vibration of C—H of aromatic ring, ininfrared spectroscopy spectrum (results are not shown).

Also, it was analyzed that polyaniline had peaks at about 137 ppm andabout 141 ppm of chemical shifts in ¹³C NMR spectrum, which are typicalpeaks of polyaniline (result not shown). Especially, polyanilinesynthesized in this example had higher peak intensity at about 137 ppmthan peak intensity at about 141 ppm, which is resulted fromortho-coupling, in ¹³C NMR spectrum. Therefore, it was certified thatpolyaniline in this example was synthesized mainly by para-coupling, notortho-coupling and has much less side chains compared to conventionalpolyaniline.

Example 2

The procedures and conditions were repeated as example 1, except thatpolymerization reaction was performed at about −25° C. Polymerizationreaction were performed for 4˜6 hours. It was certified that obtainedmaterial was polyaniline of emeraldine base form through infraredspectroscopy and NMR technology (results are not shown).

Examples 3

The procedures and conditions were repeated as example 1, except thatammonium persulfate as a radical initiator was added drop wise for 3hours. Polymerization reaction were performed for 3˜8 hours. It wascertified that obtained material was polyaniline of emeraldine base formthrough infrared spectroscopy and NMR technology (results are notshown).

Example 4

The procedures and condition were repeated as example 3, except thatferric chloride as a radical initiator was added to the reaction systemprior to changing color of reaction vessel from blue to green. Ferricchloride was added 0.1 molar equivalents to HCl 0.1 moles.Polymerization was performed for 3˜6 hours. It was certified thatobtained material was polyaniline of emeraldine base form throughinfrared spectroscopy and NMR technology (results are not shown).

Example 5

The procedures and conditions were repeated as example 1, except thatchloroform instead of isopropyl alcohol as the organic solvent was used.The ratios of chloroform to hydrochloric acid solution dissolvinganiline monomer were respectively 2:1 and 1:1 by volume, andpolymerization reaction was performed for 3˜6 hours. It was certifiedthat each of obtained materials is polyaniline of EB form with infraredspectroscopy and NMR technology (results are not shown).

Example 6

The procedures and conditions were repeated as example 1, except thatmixed solvent of chloroform and isopropyl alcohol (v/v=1:1) instead ofisopropyl alcohol as the organic solvent was used. The ratios of mixedsolvent to hydrochloric acid solution dissolving aniline monomer wererespectively 2:1 and 1:1 by volume, and polymerization reaction wasperformed for 3˜6 hours. It was certified that each of obtainedmaterials is polyaniline of EB form with infrared spectroscopy and NMRtechnology (results are not shown).

Example 7

The procedures and conditions were repeated as example 2, except thatmixed solvent of chloroform and 4-methyl-2-pentanone (v/v=1:1) insteadof isopropyl alcohol as the organic solvent was used. The ratio of mixedsolvent to hydrochloric acid solution dissolving aniline monomer was 2:1by volume, and polymerization reaction was performed at for 6-10 hours.It was certified that each of obtained materials is polyaniline of EBform with infrared spectroscopy and NMR technology (results are notshown).

Example 8

Polyaniline substituted with alkyl group on the aromatic ring wassynthesized in this example. Amine group of o-hydroxyl aniline wasreacted with acetic anhydride to protect the amine group, and thenprotected aniline was reacted with hexane bromide in basic condition tosubstitute the aniline with alkyl group (hexyl group) on the aromaticring. The protected amine group of obtained product was deprotected withhydrochloric acid to produce aniline derivative substituted with alkylgroup on the aromatic ring.

5 g of the synthesized aniline derivative was added drop wise into 300mL of 1M HCl solution, and the 200 mL of dichloro methane was mixed tothe solution. The solution was maintained at −5° C., 100 mL of 1M HClsolution dissolving 1.2 g of ammonium persulfate was added drop wise tothe mixed solution for 40 minutes with stirring. After 24 hours,obtained solution was separated to extract organic layer with separatoryfunnel. The extracted organic layer was transferred to 200 mL of 1Mammonium hydroxide (NH₄OH), stirred for 24 hours, filtered, and thendried for 24 hours with vacuum pump to yield 1.5 g of polyaniline ofemeraldine base. It was certified that obtained material is polyanilineof EB form with infrared spectroscopy and NMR technology (results arenot shown).

Example 9

The procedure was repeated as example 1, except carboxylic acid monomerrepresented by structure below, which is disclosed in example 5 ofinternational patent publication No. WO 02-074833 as a solubleself-oriented material, was mixed to the reaction system in the ratio of15% by weight to aniline monomer.

It was determined that the polymer by polymerization reaction hasboard-shaped particles, which was different form the polymer in example2 not adding the soluble self-oriented material. It was certified thatobtained polymer was polyaniline of emeraldine base form with infraredspectroscopy and NMR technology (results are not shown).

Comparative Example 1 Preparation of Polyaniline by Conventional Method

Polyaniline of emeraldine base (EB) was prepared according toconventional MacDiarmid method (MacDiarmid et al., Conducting PolymersEd. By Alcacer, Dordrecht, 105, 1987).

Solution of 10 mL of distilled and purified aniline dissolved in 600 mLof 1M HCl was introduced into Erlenmeyer flask. Solution of 5.6 g ofammonium persulfate dissolved in 200 mL of 1M HCl was added slowlydropwise into the flask for 15 minutes with stirring to formpolyaniline. After 2 hours, the polymerization reaction was completed toobtain precipitate. The obtained precipitate was filtered with filterpaper and washed with 100 mL of ammonium hydroxide. The washedprecipitate was transferred to 500 mL solution of 0.1M ammoniumhydroxide, stirred for 20 hours, filtered, and dried with vacuum pumpfor 48 hours to yield 1.5 g of polyaniline of emeraldine base. It wascertified that the synthesized polymers were polyaniline EB form withinfrared spectroscopy and NMR analysis (results are not shown).

Comparative Examples 2˜4 Preparation of Polyaniline

The procedures and conditions were repeated as comparative example 1,except that each of the polymerization reaction was performedrespectively at −5° C. for 4 hours, −10° C. for 10 hours and at −15° C.for 17 hours with addition of 3M LiCl. It was certified that each ofobtained materials is polyaniline of EB form with infrared spectroscopyand NMR technology (results are not shown).

Example 10 Measurement of Intrinsic Viscosity of Polyaniline

Highly conductive polyaniline (HCPANI) of emeraldine base formsynthesized in examples 1 to 9 and conventional polyaniline (PANI) ofemeraldine base from synthesized in comparative examples 1 to 4 werededoped with ammonium hydroxide, dissolved in strong sulfuric acid of0.1 g/dl. And then intrinsic viscosity (η) of HCPANI and PANI weredetermined at 30° C. Table 1 shows the results of intrinsic viscosityfor HCPANI and PANI. It was certified that all the synthetic compoundswere polymers from measuring the intrinsic viscosity. TABLE 1 IntrinsicViscosity EXAMPLE Intrinsic Viscosity (dl/g) 1 2.2 2 2.5 3 2.4 4 1.8 52.2-2.3 6 2.7 7 2.9 8 0.2 9 1.3 Comparative Example 1 0.8 ComparativeExample 2 1.1 Comparative Example 3 1.1 Comparative Example 4 1.2

Example 11 Measurement of Optical Properties of Polyaniline

Solid powder polyaniline HCPANI of EB form (HCPANI) synthesized inexample 1 and solid powder polyaniline of EB from (PANI) synthesized incomparative example 1 were analyzed with ¹³C CPMAS-NMR and PASspectroscopy. ¹³C CPMAS-NMR spectrum was measured at 100.6 MHz andspinning rate 7 KHz in tetramethyl silane (TMS) as standard with BrukerNMR instrument. PAS spectrum was measured in helium with infraredspectrometer (Magna 550 PAS detector).

FIG. 2 shows a ¹³C CPMAS NMR analysis result of HCPANI synthesized inexample 1. FIG. 3 shows a ¹³C CPMAS NMR analysis result of PANIsynthesized in comparative example 1. FIG. 4 shows a PAS analysis resultof HCPANI synthesized in example 1. FIG. 5 shows a PAS analysis resultof PANI synthesized in comparative example 1.

As shown in FIG. 2, HCPANI synthesized according to example 1 has 2remarkably distinguishable peaks at around 140 ppm of chemical shift,that is, at about 138 ppm and at about 143 ppm of chemical shift, in ¹³CCPMAS NMR spectrum, and especially a unique peat at about 138 ppm ofchemical shift. Also, the peak intensity at about 138 ppm of chemicalshift (I₁₃₈) is higher than the peak intensity at about 143 ppm ofchemical shift (I₁₄₃). Besides, HCPANI has respectively a unique peakeach at about 158 ppm and at about 127 ppm of chemical shift notmultiple or composite peaks at such chemical shifts, which demonstratesstructural superiority of HCPANI.

Besides, HCPANI had two relatively weak peaks at about 1107 cm⁻¹ in PASspectrum as shown in FIG. 4, on the other hand conventional PANI had arelatively strong peak at about 1107 cm⁻¹ in PAS spectrum as shown inFIG. 5.

Example 12 Observation of Particle Formation

HCPANI powder of EB forms synthesized in above Examples 1 to 5 and PANIpowder of EB from synthesized in comparative example 1 was analyzed withscanning electron microscopy in this example. FIGS. 6A, 6B, 6C, 6D, and6E to 6F shows respectively a electron microscopy of particle structureof configuration for HCPANI powder of EB form synthesized in each ofExample 1, Example 2, Example 3, Example 4, and Example 5.

As shown the figures, all of HCPANI particles synthesized according tothe preferred example of the present invention show holes such as“foamed plastics”, a hollow quadra-angular rod (or bar) shape like“honeycomb”, or multiple layers such as “anion coat”. In other words, itwas analyzed that HCPANI particle of the present invention has stericconfiguration of much increased surface areas compared to theconventional PANI (FIGS. 7A and 7B). As shown in FIG. 6 e, which is aelectron microscopy enlarged by 30,000 for HCPANI particle synthesizedin Example 5, particles of about 20˜80 nm were assembled to form a kindof network configuration such as bunches of grapes. In other words, itwas confirmed that HCPANI produced in the present invention wassynthesized as nano-sized particles to form porous networkconfigurations. Therefore, it is expected that the conductive polymerssynthesized according to the present invention is synthesized as linearchains and thereby increasing their solubility in common organicsolvents.

On the other hand, polyaniline synthesized according to the conventionMacDiarmid method in comparative example 1 (PANI) has only compactstructure, not network configuration, as shown in FIGS. 7A and 7B.

However, HCPANI powder of EB form synthesized in Example 1 had a meanarea of 145 microns and a mean volume of 230 microns, while polyanilinepowder of EB form synthesized in comparative example 1 had a mean areaof 7 microns and a mean volume of 18 microns, in the particle analysisby light scattering.

Example 13 Measurement of Apparent Density

In this example, the apparent density of HCPANI powder of EB formssynthesized according to above examples 1 to 6 was measured. Theapparent density of polyaniline was measured by calculating injectionamount of each polymer from specified funnel by American Society forTesting and Materials (ASTM) D1895-96.

As described in above Example 12, HCPANI has characteristic particlesand pores, which increases its surface area and thereby enhancingsolubility to common solvents. Also, the apparent density, which means amass per unit volume of particle, is one important physical property.

It was measured that HCPANI synthesized according to the presentinvention had apparent density of 0.0495˜0.146 (g/cm³), which is verylow compared to conventional polyaniline.

Example 14 Measurement of Electrical Conductivity of Polyaniline asPellet

In this example, electrical conductivity of HCPANI salts synthesized inexamples 1 to 9 and PANI salts synthesized in comparative examples 1 to4 as pellets were measured as described above. It was determined thatHCPANI salts synthesized in Examples 1 to 4 has electrical conductivityof 16˜38 S/cm, while PANI salts synthesized in comparative examples 1 to4 has electrical conductivity of 2˜5 S/cm.

Example 15 Measurement of Electrical Conductivity of Polyaniline in CSASolution

In this example, both HCPANI salts synthesized in Examples 1 to 7 andPANI salts synthesized in comparative examples 1-4 were dedoped toobtain polyaniline of emeraldine base. 1.5/g of camphor sulfonic acid(CSA) was mixed with respective 1.23 g of polyaniline EB (molarequivalent of 1:2). The mixtures are dissolved in meta-cresol withconcentration of 2% (w/w) and the solution was prepared by sonicationfor 2 hours. 0.5 mL of the solution was casted on slide glass and driedat 50° C. to manufacture film samples with a thickness of 0.5˜80 μm.Electrical conductivity was performed on 3 film samples manufacturedfrom each polyaniline as mentioned above. Table 2 shows mean electricalconductivity measured on each polyaniline film. TABLE 2 ElectricalConductivity EXAMPLE Electrical Conductivity(S/cm) 1  690 2  810 3  7604  660 5 860-920 6 1180 7 1350 8  10 9  510*   480** Comparative Example1  210 Comparative Example 2  170 Comparative Example 3  250 ComparativeExample 4  190*after polymerization reaction, soluble self oriented material isdeleted.**after polymerization reaction, soluble self oriented material iscomprised.

Example 16 Measurement of UV-VIS-NIR Spectrum

Polyaniline of EB form synthesized in Example 2 was changed topolyaniline salt as Example 15, and then the salt was measured withUV-VIS-NIR spectrophotometer in this Example. FIG. 8 shows an analyticalresult of UV-VIS-NIR spectrophotometer for emeraldine base doped withcamphor sulfonic acid (EB-CSA).

In UV-VIS-NIR spectrum for polyaniline of emeraldine salt, free carriertail which contributes to enhancing electrical conductivity of the saltusually initiates at no less than 1000 nm. However, as shown in FIG. 8,it was observed that the emeraldine salt synthesized in Example 2 doesnot show a localized polaron band at around 1000 nm of wavelength, butshows a continued increased absorbency line. Especially, the emeraldinesalt synthesized in Example 2 had a strong polaron band by comparing thepeak intensity of meta-cresol at about 300 nm to the peak intensity atabout 2000 nm by polaron band.

Such a result supports the reason structurally that the emeraldine baseof Example 2 had high electrical conductivity as indicated in table 2above. The strong absorbency at near infrared rays (about 2000 mwavelength) is similar to the absorbency for metals. In other words, itis expected that polyaniline of emeraldine salt synthesized according tothe preferred examples of the present SSDP process has “true metal”properties and therefore, may be used for EMI shield, unlike theconventional polyaniline emeraldine salt which has disorderedproperties.

Example 17 Measurement of Molecular Weight and Distribution Degree withGPC

Polyaniline with enhanced solubility was synthesized by substituting itwith t-BOC in this Example according to the literature procedure (Lee etal, Macromolecules, 34, p4070, 2004). Polyaniline was prepared with thesame procedures and condition as Example 1.

1.0 g (5.5×10⁻³ mole) of the synthesized emeraldine base and 4.8 g(2.2×10-2 mole) of di-tert-butyloxocarbonyl (di-t-BOC) were dissolved in30 mL of NMP. 20 mL of pyridine was added into the solution, and thenthe solution was stirred at 90° C. for 6 hours. The reaction product wasprecipitated with excessive water to filter, washed with solution ofwater and ethanol (1:1) to yield pure 0.6 g of t-BOC substitutedpolyaniline (HCPANI-tBOC). The obtained HCPANI-t-BOC was dissolved intetrahydrofurane (THF), and then its molecular weight and molecularweight distribution are measured with gel permeation chromatography(GPC, Waters Co.)

It was determined that t-BOC substituted polyaniline had a numberaverage molecular weight of 44,000 and a weight average molecular weightof 46,000. Besides, it wad analyzed that t-BOC substituted polyanilinehad a molecular weight distribution degree of 1.1, which means t-BOCsubstituted polyaniline in this example had substantially mono-dispersedistribution.

Example 18 NMR Analysis of Polyaniline

HCPANI synthesized according to Example 1 was analyzed by NMR in thisExample. HCPANI salts of Example 1 was substituted withtert-butoxycarbonyl (t-BOC) to enhance solubility thereof for certifyingits structures in solution state NMR analysis (C¹³ NMR, Jeol YH400).

Introduction of t-BOC group into HCPANI was performed in accordance withliterature (Lee et al., Macromolecules, 2004, 37, pp. 4070-4074). 4.0 gof each polyaniline powder and 13 mL of pyridine was added in 100 mL ofN-methylpyrrolidinone (NMP), into which a solution comprising 9 g ofdi-tert-butyldicarbonate dissolved in 50 mL of NMP were added slowly at80° C. The mixed solution was stirred in nitrogen reflux for 3 hours toobtain product. The product was washed with methanol and dried to yieldpale dark reddish powders.

Such powders were dissolved in CDCl₃, which is solvent of NMR, to obtain¹³C NMR spectra. FIG. 9 shows an NMR analysis result of HCPANIsubstituted with t-BOC of the present invention. As shown the figures,it was determined that HCPANI-t-BOC had three peaks, which correspond toquaternary carbons, at about 140 ppm, about 148 ppm, and about 159 ppmof chemical shifts in solution state ¹³C NMR spectrum.

Example 19 Measurement of Molecular Weight and Distribution Degree withGPC

1.0 g (5.5×10⁻³ mole) of the synthesized emeraldine base and 1.2 g ofphenyl hydrazine were dissolved in 30 mL of NMP, and then reducedpolyaniline was precipitated to 1 L of desiccated toluene. Theprecipitated polyaniline was washed 3 times with toluene to yield 0.5 gof yellowish brown leucoemeraldine base powder.

The produced leucoemeraldine base was dissolved in NMP, and then itsmolecular weight and molecular weight distribution are measured with GPC(Waters Co.). Polyvinyl pyridine was used to determine molecular weightand distribution degree of polyaniline as a standard sample. It wasdetermined that leucoemeraldine base had respectively a number averagemolecular weight of 45,000 and 37,000, weight average molecular weightof 112,000 and 87,000, and distribution degree of 2.5 and 2.4, accordingto the ratio of 2:1 and 1:1 of polymer to solvent. FIG. 10 shows adistribution of molecular weight of highly conductive polyanilinesynthesized according to the present invention by GPC.

Angelopoulos et al. reported that synthesizing polyaniline byconventional MacDiarmid method resulted in high molecular weightpolyaniline and low molecular weight polyaniline and thereby showingvarious peaks. Especially, high molecular weight polyaniline comprisesnothing but 4˜10% among produced polymers, and synthesized polymers hadbroad degree of dispersion of about 3.7 to 6.6 (Angelopulos et al.,Synth. Met. 84, p 35, 1997). On the other hand, the highmolecular-weight polymer according to this example shows a unique peak,not separated peaks, and lower molecular distribution degree as shown inFIG. 9.

Example 20 Preparation Polypyrrole

A solution comprising 33.5 g (0.5 mol) of distilled and purified pyrroledissolved in 1.0 L of 1M HCl was added drop wise to 500 mL ofchloroform, and then the solution was maintained in the temperature of−5° C. Solution of 0.1 mol of ammonium persulfate ((NH₄)₂S₂O₈), as anradical initiator, dissolved in 100 mL of 1M HCl was added slowly intothe above mixed solution for 10 minutes with stirring intensively toinitiate polymerization reaction. After 40 hours, the polymerizationreaction was completed. The mixed solution was poured into methanolsolution, and washed with distilled water several times. Residualprecipitate was filtered, and then dried in vacuum oven for 24 hours.Obtained precipitate was transferred into 1 L of 1M ammonium hydroxide,stirred 20 hours, washed with water, and then dried with vacuum pump for48 hours to yield 11 g of polypyrrole.

It was determined that polypyrrole in this example had inherentviscosity of 0.3 (in MMP) and that polypyrrole particle doped with HClhad electrical conductivity of 45 S/cm.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the fabrication andapplication of the present invention without departing from the spiritor scope of the invention. Thus, it is intended that the presentinvention cover the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents.

1. A process of synthesizing a conductive polymer, the processcomprising: (a) mixing a monomer substituted with an amine group and anorganic solvent with an acid solution; and (b) adding a radicalinitiator dissolved in a protonic acid into the acid solution tosynthesize the conductive polymer.
 2. The process according to claim 1,wherein the monomer substituted with the amine group is mixed with theacid solution prior to the organic solvent.
 3. The process according toclaim 1, wherein the monomer substituted with the amine group has astructure represented by formula I below.

wherein R₁ is hydrogen, alkyl, or alkoxy group; and each R₂ to R₅ isrespectively hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl,alkyl-thioalkyl, alkanoyl, thioalkyl, aryl-alkyl, alkyl-amino, amino,alkoxy carbonyl, alkyl sulfonyl, alkyl sulfinyl, thioaryl, sulfonyl,carboxyl, hydroxyl, halogen, nitro, or alkyl-aryl.
 4. The processaccording to claim 1, wherein the monomer substituted with the aminogroup has a structure represented by formula II below.

wherein R₁ is hydrogen, alkyl, or alkoxy group; and each R₂ and R₃ isrespectively hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl,alkyl-thioalkyl, alkanoyl, thioalkyl, aryl-alkyl, alkyl-amino, amino,alkoxy carbonyl, alkyl sulfonyl, alkyl sulfinyl, thioaryl, sulfonyl,carboxyl, hydroxyl, halogen, nitro, or alkyl-aryl.
 5. The processaccording to claim 1, wherein the acid comprises inorganic acid.
 6. Theprocess according to claim 1, wherein the acid is selected from thegroup consisting of hydrochloric acid, sulfuric acid, nitric acid, orphosphoric acid.
 7. The process according to claim 1, wherein theprotonic acid comprises an inorganic acid.
 8. The process according toclaim 7, wherein the inorganic acid is selected from the groupconsisting of hydrochloric acid, nitric acid, sulfuric acid, phosphoricacid, hydrofluoric acid, or hydroiodic acid or mixtures thereof.
 9. Theprocess according to claim 1, wherein the protonic acid comprises anorganic acid.
 10. The process according to claim 9, wherein the organicacid is selected from the group consisting of methyl sulfonic acid,dodecyl benzene sulfonic acid, antraquinone-2-sulfonic acid,4-sulfosalicylic acid, camphor sulfonic acid, chlorinated sulfonic acid,trifluoro-sulfonic acid.
 11. The process according to claim 1, whereinthe organic solvent has a solubility parameter of about 17 to about 29.12. The process according to claim 1, wherein the organic solventcomprises hydrocarbons unsubstituted or substituted with hydroxyl,halogen, oxygen, ketone, or carboxyl group.
 13. The process according toclaim 1, wherein the organic solvent is an alkyl halide.
 14. The processaccording to claim 1, wherein the organic solvent comprisesdichloromethane, pentachloro ethane, 1,1,2,2-tetrachloro ethane,trichloro ethane, trichloro ethylene, dichloro methane, chloroform,ethyl bromide, ethyl chloride, dichloro propane, trichloro ethane,bis(2-chloroethyl)ether, dichloro ethyl ether, 1,2-dichloro benzene, ormixtures thereof.
 15. The process according to claim 1, wherein theorganic solvent is selected from the group consisting of comprise1-propanol, 2-methyl-2-propanol, 1,2-dipropandiol, 1,3-propandiol,isopropyl alcohol, butanol, neopentanol, 2-methoxy ethanol, 2-butoxyethanol, 2-ethyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol,3-methyl-2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1,2-propanediol,1,5-pentandiol, amylalcohol, 2-methyl-1-pentanol, 3-methyl-1-pentanol,2-methyl-2-pentanol, 3-methyl-2-pentanol, 4-methyl-2-pentanol,2-methyl-3-pentanol, 3-methyl3-pentanol, hexanol, ethyl hexanol,heptanol, 3-heptanol, 2-methyl-2,4-pentandiol, 2-ethyl-1,3-hexandiol,octanol, 1-octanol, 2-octanol, decanol, dodecanol, cyclohexanol,tri-ethylene glycol, di-ethylene glycol, tetra-ethylene glycol,tetra-hydrofurfuryl alcohol, or mixtures thereof.
 16. The processaccording to claim 1, wherein the organic solvent comprises ethyleneglycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycolmonomethyl ether, ethylene glycol monobutyl ether, diethylene glycolmonoethyl ether or diethylene glycol monobutyl ether, diethylene glycoldiethyl ether, diethylene glycol dimethyl ether, diethylene glycolmonomethyl ether, 1,4-dioxane, or mixtures thereof.
 17. The processaccording to claim 1, wherein the organic solvent comprises butyl methylketone, methyl-ethyl ketone, 4-hydroxy-4-methyl-2-pentanone,cyclopentanone, diacetone alcohol, 4-methyhl-pentanone,4-methyl-2-pentanone, or mixtures thereof.
 18. The process according toclaim 1, wherein the organic solvent comprises diethyl carbonate, benzylacetate, dimethyl glutarate, ethylacetoacetate, isobutyl isobutanoate,isobutyl acetate, meta-cresol, toluene, xylene, nitrobenzene,tetrahydrofuran, N-methyl-2-pyrolidone, dimethyl sulfoxide,N,N-dimethylformamide, or mixtures thereof.
 19. The process according toclaim 1, wherein the radical initiator comprises ammonium persulfate,hydrogen peroxide, manganese dioxide, potassium dichromate, potassiumiodate, ferric chloride, potassium permanganate, potassium bromate,potassium chlorate, or mixtures thereof.
 20. The process according toclaim 1, wherein step (b) is performed in the temperature of betweenabout −45° C. to about 40° C.
 21. The process according to claim 1,wherein the radical initiator and the organic solvent comprises anorganic phase, wherein the organic phase comprises about 5˜95% by weightbased upon total aqueous solution.
 22. The process according to claim 2,further comprising step (c) dedoping the conductive polymer with a base.23. The process according to claim 22, wherein the base compriseshydroxide compounds.
 24. A conductive polymer synthesized according toclaim 1, wherein the conductive polymer has a hollow quadra-angular rodshape and honeycombed network configuration.
 25. The conductive polymeraccording to claim 24, wherein the conductive polymer is consisted ofnanometer particles.
 26. The conductive polymer according to claim 24,wherein the conductive polymer is consisted of nanometer tubes.
 27. Theconductive polymer according to claim 24, wherein the conductive polymeris consisted of nano-fibers.
 28. The conductive polymer according toclaim 24, wherein the conductive polymer has an apparent density in therange of about 0.03˜0.19 measured in ASTM Standard D1895-6.
 29. Aconductive polymer synthesized according to claim 1, wherein theconductive polymer has an electrical conductivity of at least about 300S/cm.
 30. The conductive polymer according to claim 29, wherein theconductive polymer has an electrical conductivity of at least about 500S/cm.
 31. The conductive polymer according to claim 29, wherein theconductive polymer has an electrical conductivity of at least about 700S/cm.
 32. The conductive polymer according to claim 29, wherein theconductive polymer has an electrical conductivity of at least about 900S/cm.
 33. The conductive polymer according to claim 29, wherein theconductive polymer has an electrical conductivity is at least about 1100S/cm.
 34. The conductive polymer according to claim 27, wherein theconductive polymer has an electrical conductivity of at least about 1300S/cm.
 35. A conductive polymer synthesized according to claim 22,wherein the conductive polymer has a hollow quadra-angular rod shape andhoneycombed network configuration, wherein the conductive polymer has arepeat unit represented by the formula below and the conductive polymerhas at least one single peak at about 123 ppm of chemical shift and atabout 158 ppm of chemical shift in a ¹³C CPMAS NMR spectrum and/or hasidentifiable peaks at around 140 ppm of chemical shift in a ¹³C CPMASNMR spectrum.

wherein x and y is respectively a molar fraction of quinonediiminestructural unit and phenylenediamine structural unit in the repeatingunit, and 0<x<1, 0<y<1 and x+y=1; and n is an integer of 2 or more. 36.The conductive polymer according to claim 35, wherein the conductivepolymer forms peaks at about 138 ppm of chemical shift and at about 143ppm of chemical shift in a ¹³C CPMAS NMR spectrum.
 37. The conductivepolymer according to claim 35, wherein the conductive polymer has I₁₃₈larger than I₁₄₃, wherein I₁₃₈ represents a peak intensity at about 138ppm of chemical shift in the ¹³C CPMAS NMR spectrum and I₁₄₃ representsa peak intensity at about 143 ppm of chemical shift in the ¹³C CPMAS NMRspectrum.
 38. The conductive polymer according to claim 37, wherein theconductive polymer has a peak intensity ratio, I ₁₃₈/I₁₄₃, of equal toor more than 1.2 in the ¹³C CPMAS NMR spectrum.
 39. The conductivepolymer according to claim 35, wherein the conductive polymer has twopeaks at about wavelength 1107 cm⁻¹ in PAS spectrum.
 40. A polyanilinehaving a repeat unit represented by the formula below, wherein thepolyaniline has three main peaks corresponding to quaternary carbon in asolution state ¹³C NMR spectrum in case the polyaniline is substitutedwith tert-butoxycarbonyl. [Formula]

wherein x and y is respectively a molar fraction of a quinonediiminestructural unit and phenylenediamine structural unit in the repeatingunit, and 0<x<1, 0<y<1 and x+y=1; and n is an integer of 2 or more.